The object is to move all the frogs from one side to the other- they can only hop or slide in the direction they are facing (click on a frog above to make him hop).

Could you solve a simpler puzzle with only 1 or 2 frogs on one side of the empty space? Count the number of moves needed to solve each puzzle, and put them in the table below. I counted the moves in a puzzle with 5 frogs. Can you find a pattern that might give the number of moves to solve a puzzle with 4 frogs on one side of the empty space? This applet may help you count.

Extra Credit: Explain *why* this pattern works for these puzzles...

Number of frogs on one side of the empty space
Number of moves to solve the puzzle
1

2

3 (this puzzle)

4

5
35